Portable collapsible liquid containment devices are used to prevent hazardous fluids from entering the environment from, for example, spillage of the fluids during loading and unloading of transport vehicles, wash-down of equipment and vehicles, and repair/maintenance of equipment and vehicles. Typically one or more sides of the containment device can be lowered and laid flat so that the equipment or vehicle can easily enter the containment area. Once the equipment or vehicle is inside, the sidewall(s) are then raised to prevent fluids from escaping. Any spilled fluid or wash-down fluid is retained within the container and can be pumped out for proper disposal. After the container is emptied, the sidewall(s) can be lowered again to remove the equipment or vehicle. The container can then be folded or rolled-up for storage and transport.
Such containment devices are typically made with a flexible barrier material, such as a rubberized fabric, reinforced polyvinyl chloride (PVC), reinforced thermoplastic polyurethane (TPU) and/or a heavy gauge polymer film. During use, the containment device is unfolded/unrolled and the sides extended to a generally vertical position to achieve its fluid retaining capability. To maintain the sidewalls in this generally vertical position, collapsible sidewall braces may be employed, as exemplified in U.S. Pat. Nos. 5,316,175; 5,762,233; 6,092,686; 6,880,720; and 8,562,251 and published US Patent Application Nos. 2013/0240538 and 2014/0246441, which are incorporated herein by reference.